Pulsed eddy current near-remote-field hybird quantitative detection of metal component defects

In view of the advantages of pulsed eddy current testing (PEC) and pulsed remote-field eddy current testing (PRFEC) in detection of damages in metallic components, in this paper a new probe structure was proposed for realization of the near-field and remote-field pulsed eddy current hybrid testing (NRPEC) of defects in NFCs. Through numerical simulations, based on the analysis regarding the energy density of electromagnetic field, the signal characteristics of NRPEC and its response sensitivity to wall-thinning defects were scrutinized. The correlation between the signal feature and defect sizing parameters was analyzed. In parallel, an experimental platform of NRPEC had been built up. Through a series of experiments of NRPEC, detection and quantitative evaluation of wall-thinning defects in NFCs were further investigated. It was found from simulations and experiments that the proposed probe structure integrating the measurement of direct and indirect coupling components of magnetic field was applicable for simultaneous implementation of near-field and remote-field inspection of wall-thinning defects in NFCs, enhancing extraction of quantitative information regarding the defects under non-invasive interrogation.